CN102539107B - Method for accurately synchronizing test signals of wind tunnel - Google Patents
Method for accurately synchronizing test signals of wind tunnel Download PDFInfo
- Publication number
- CN102539107B CN102539107B CN201210036066.7A CN201210036066A CN102539107B CN 102539107 B CN102539107 B CN 102539107B CN 201210036066 A CN201210036066 A CN 201210036066A CN 102539107 B CN102539107 B CN 102539107B
- Authority
- CN
- China
- Prior art keywords
- attitude angle
- data
- component
- wind tunnel
- strain balance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Abstract
The invention provides a method for accurately synchronizing test signals of a wind tunnel. The method comprises the following steps of: 1, measuring a delay time difference, namely changing an aircraft model arranged in the wind tunnel back and forth in an attitude angle variation region according to given velocity, acquiring data of all component output signals of a strain balance and data of output signals of an attitude angle sensor uniformly, continuously and synchronously according to a certain acquisition rate through a measurement system, transmitting into a computer, performing computational analysis on cross-correlation functions between the data of all the component output signals of the strain balance and the data of the output signals of the attitude angle sensor respectively through the computer, and solving the delay time difference between all component electrical signals of the strain balance and electrical signals of the attitude angle sensor; and 2, performing synchronous correction, namely performing accurate synchronous correction on the data of all the measured component electrical signals of the strain balance according to the acquired delay time difference in the wind tunnel test process. The method has the outstanding advantage of capability of accurately synchronizing the test signals of the wind tunnel finally.
Description
Technical field
The present invention relates to aerospace industry aerodynamics wind-tunnel technique field, especially relate to a kind of method that realizes all kinds of measuring-signal precise synchronizations in the high-speed wind tunnel test.
Background technology
Wind tunnel force measurement test is the most basic wind tunnel test project of dummy vehicle, and purpose is the aerodynamic characteristics when measuring aircraft and changing with attitude angle, requires accurately to provide aircraft aerodynamic force and aerodynamic moment value accordingly under certain special angle.In wind tunnel test, the attitude angle of aircraft is obtained by angular transducer or displacement sensor usually, and aerodynamic force and aerodynamic moment are measured by resistance-strain balance (being generally six COMPONENT BALANCE).Because the response characteristic of angular transducer, displacement transducer and balance is different, so there is certain difference of injection time between signal, at present, without effective measurement means, it is carried out to quantitative analysis temporarily during wind tunnel test, make the sequential relationship between unlike signal be difficult to determine, finally cause the measurement of aerodynamic force and aerodynamic moment and attitude angle asynchronous.
Before this, it is upper that the synchronism research of wind-tunnel measurements signal both at home and abroad only is confined to the synchronism research of electric signal transmission and collection mostly, and ignored the asynchronism(-nization) of multiple sensors physical responses is walked affect correction research.When test signal is had to the precise synchronization requirement, normally adopt to reduce model attitude angle travelling speed or the model stop motion waited for synchronous, respond the asynchronous and skew test figure that causes to reduce and to eliminate sensor.As the external continuous change angle of attack dynamometer check of wind-tunnel continuously, for the asynchronous impact on test figure of erasure signal, generally all adopt lower angle of attack travelling speed (0.1 °/s～0.5 °/s); Domestic high-speed wind tunnel is owing to being mostly the formula of rushing temporarily, be subject to source of the gas volume and the restriction of wind tunnel operation time, can only adopt for a long time the less ladder dynamometer check mode in testing site, after angle of attack arrives specified angle, stop motion, stablize 0.5～1 second, eliminate asynchronous after, then the data of acquisition test signal.
In recent years, along with the domestic formula high-speed wind tunnel that rushes temporarily becomes carrying out of angle of attack dynamometer check technical research work continuously, because can not reduce model attitude angle travelling speed, can not make the model stop motion wait for synchronous, make because the asynchronous problem that affects on test figure of measuring-signal that the sensor physical responses postpones to cause highlights, cause aerodynamic characteristics curve generation translation phenomenon, have a strong impact on the accuracy of dynamometer check data.
Summary of the invention
The object of the invention is to: the problem existed for prior art provides a kind of method that can finally realize the test signals of wind tunnel precise synchronization.
The present invention is achieved by the following technical solutions, comprises the following steps:
(1) dummy vehicle that will be arranged in wind-tunnel is by given speed at an attitude angle constant interval, and the attitude angle of aircraft is changed from small to big, more from large to small, repeats back and forth secondary; Measuring system is according to the data of each component output signal of collection strain balance of certain even continuous synchronization of acquisition rate and the data of attitude angle transducer output signal simultaneously;
(2) computing machine carries out the cross correlation function computational analysis to the data of each component output signal of strain balance and the data of attitude angle transducer output signal, calculates each component electric signal of strain balance of collection and the delay time difference between the attitude angle transducer electric signal;
(3) during wind tunnel test, acquisition system is according to the data of the acquisition rate acquisition test signal in step (1), then the delay time difference obtained according to step (2), the sequential of attitude angle transducer electric signal of take is standard time sequence, the data of each component electric signal of strain balance of recording are carried out to accurate synchronous the correction, finally obtain the test figure of Complete Synchronization.
Definite method of the attitude angle constant interval in described step (1) is that the function rule according to each component of strain balance with the attitude angle conversion of aircraft, select the strain balance component to change the curve interval that approaches linear change with attitude angle.
Certain acquisition rate in described step (1) meets: the resolution of acquisition rate >=1/ time.
Described step (2) specifically comprises the following steps:
(2.1) computing machine from synchronous acquisition to data isolate the time dependent curvilinear function of each component of balance and the time dependent curvilinear function of attitude angle;
(2.2) according to the cross correlation function formula
, calculate respectively the cross correlation function of the output signal function of the output signal function of each component of strain balance and attitude angle transducer; X in formula (t) is the output signal function of attitude angle transducer, and y (t) is respectively the output signal function of each component of strain balance, and t is the time, and T is the total duration of sampling;
(2.3) calculate cross correlation function R
xy(τ) value of the τ at place, top, this value is exactly the delay time difference gathered between strain balance component electric signal and attitude angle transducer electric signal.
Further comprising the steps of: as the data of the data of each component output signal of strain balance of collecting and attitude angle transducer output signal to be carried out to nothing and postpone digital filtering and process, eliminate the noise that acquisition system is brought into.
Compared with prior art, the present invention can accurately obtain small asynchronous between test signals of wind tunnel, and then the foundation of the data of test signal being carried out to the precise synchronization correction is provided, and finally realizes the precise synchronization of test signals of wind tunnel.
Embodiment
Below in conjunction with specific embodiment, the present invention is described in detail.
A kind of method that realizes the test signals of wind tunnel precise synchronization of embodiment
The present invention is in order thoroughly to solve the asynchronous problem between various signals in wind tunnel test, set up between balance, sensor measured value and model attitude angular measurement value sequential corresponding relation accurately, the aerodynamic characteristic Changing Pattern of correct reflection dummy vehicle, the accuracy that improves results of wind tunnel.The method that the present invention proposes mainly comprises the following steps:
Step 1: before wind tunnel test, the function rule first changed with model (aircraft) attitude angle according to each component of strain balance, select the strain balance component with the curve segment test days amount of dividing equally of attitude angle linear change and the delay time difference between attitude angle transducer as far as possible, starting attitude angle during test changes from small to big in the attitude angle constant interval of having selected by given speed, again from large to small, repeat back and forth secondary, the output of the collection balance component of the even continuous synchronization of the acquisition rate (resolution of acquisition rate >=1/ time) set and the output of attitude angle transducer for measuring system,
Step 2: the data of the strain balance component signal that even continuous acquisition is obtained are separated with the data of attitude angle transducer signal, obtain the time dependent curvilinear function Y of each component of balance (t), Mz (t), X (t) ... Deng, the time dependent curvilinear function α of attitude angle transducer output signal (t) etc.; Calculate respectively again Y (t) and α (t), Mz (t) the cross correlation function R with α (t), X (t) and α (t) etc.
α Y(τ), R
α Mz(τ), R
α X(τ), analyze and obtain cross correlation function R
α Y(τ), R
α Mz(τ), R
α X(τ) the time τ at maximal value place is respectively τ
y, τ
mz, τ
x, τ
y, τ
mz, τ
xbe exactly delay time difference accurately between balance component Y, Mz, X component electric signal and attitude angle transducer electric signal, if also have other sensor device, also can obtain with reference to same method the delay time difference of other pressure transducer.This step based on cardinal principle as follows:
The time history of supposing two stationary random signals is recorded as x (t) and y (t), the cross correlation function R of two signals
xy(τ) be:
According to character and the characteristics of cross correlation function, suppose that x (t) is the input signal of system, and y (t) is the output signal of system, the τ at place, the top of cross correlation function Rxy (τ) is exactly the retardation time of this system.
Below take the time history Y(t of balance lift unit signal), the time history α (t) of angle of attack sensor signal illustrates this principle and method as example.By the known Y(t of pneumatic knowledge) be the function of α (t), and in small angle range, Y(t) approximate is the linear function of α (t), therefore, α (t) can be regarded as to the input of system, and by Y(t) regard the output of system as, when model attitude angle α changes back and forth in small angle range, the Y of balance lift unit also should change accordingly back and forth, when attitude angle α is maximal value, the Y of balance lift unit should be also maximal value, when attitude angle α is minimum value, the Y of balance lift unit should be also minimum value, if and these two signals produce and the process of transmission in while having asynchrony phenomenon, the maximal value of the Y of balance lift that acquisition system records unit may be just can corresponding α maximal value.In order to obtain accurately asynchronous amount, introduce cross correlation function, utilize character and the characteristics of above-mentioned cross correlation function, ask cross correlation function R
α Y(τ) τ at top place is exactly the signal Y(t of balance lift unit) to the accurate delay time difference of model attitude angle α (t).
Delay time difference between test signals of wind tunnel is relevant to delay and the programmed acquisition processing mode of the hardware devices such as balance, attitude angle transducer, filter amplifier, data acquisition system (DAS), data acquisition program, matched combined in system is constant, be only that equipment is unloaded and is loaded on, delay time difference can not change.That is: same matched combined system only needs the measurement time lag of first order time difference to get final product.
Step 3: during wind tunnel test, acquisition system is by the data of same acquisition rate acquisition test signal, after test, delay time difference according to each component of the balance before tested and calculated to the model attitude angle transducer, the sequential of attitude angle transducer signal of take is standard time sequence, the data of each component signal of balance of recording are carried out to accurate synchronous the correction, finally obtain the data of the test original signal of Complete Synchronization.
Below take certain model aircraft dynamometer check is example, and method of testing design, the delay time difference analysis calculation method that describes delay time difference between balance signal and angle of attack sensor signal in detail reaches test signal data sync correcting method etc.
1, method of testing design
The method of testing principle of design: the one, select the interval that approaches linear function to carry out the delay time difference test as far as possible; The 2nd, the data value of two tested signals is identical or close on the order of magnitude.
1) balance Y unit, the first signal delay method of testing of Mz
The wind tunnel force measurement test, when angle of attack changes in the small angle range of 0 °～4 °, these two component signals are approaching to the function of angle of attack signal is linear function, and the signal of conventional balance is after being exaggerated 500 times, signal is thousand millivolts of orders of magnitude, the output of angle of attack sensor is also thousand millivolts of orders of magnitude, and the order of magnitude is suitable, meets above-mentioned test principle.During testing experiment, the angle of attack is from 0 °～4 °～0 °～4 °～0 ° uniform motion, the data that the acquisition system collection is whole
2) balance X unit signal delay method of testing
During the blowing test, X unit signal is with the approximate quafric curve of change in angle of attack, but when static (windless condition) change in angle of attack, X unit signal is with the approximate linearity curve of change in angle of attack, therefore the delay time difference of testing X unit signal does not need blowing, the static angle of attack is from 0 °～20 °～0 °～20 °～0 ° uniform motion, the data that the acquisition system collection is whole.
3) other signal delay method of testing
Sensor or the method for testing design of the delay time difference of other component of balance to other can be first with reference to above-mentioned Y unit, Mz, the method for testing design of the first component of X.
2, delay time difference analysis calculation method
1) test data collected is carried out to conventional processing without postponing digital filtering, eliminate the noise that acquisition system is brought into;
2) in the intercepting image data, the data of angle of attack target phase are the valid data that delay time difference calculates;
3) judge that whether Y unit, Mz is first, X is first signal be that increase with the angle of attack increases, if not, by balance unit signal opposite sign;
4) calculate respectively the cross correlation function R of balance unit's signal and angle of attack sensor signal
α Y(τ), R
α Mz(τ), R
α X(τ) and they separately the τ value at maximal value place be respectively τ
y, τ
mz, τ
x, τ
y, τ
mz, τ
xrespectively just that Y unit, Mz are first, the delay time difference value of the relative angle of attack sensor signal of the first signal of X, in the processing and calculating of actual discrete data, the data point collected of can only take is unit calculating cross correlation function, therefore the result obtained is counting of differing, and delay time difference τ=differ counts * (1/ acquisition rate)
3, test signal data sync correcting method:
1), after obtaining each yuan of signal delay of balance and count by cross correlation function, during wind tunnel test, the test original signal data that collect are carried out to synchronous alignment and revise; Clip uneven data end to end after synchronous alignment correction.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, it should be pointed out that all any modifications of doing within the spirit and principles in the present invention, be equal to replacement and improvement etc., within all should being included in protection scope of the present invention.
Claims (5)
1. a method that realizes the test signals of wind tunnel precise synchronization, is characterized in that, the method comprises the following steps:
(1) dummy vehicle that makes to be arranged in wind-tunnel moves in an attitude angle constant interval by given speed, and the attitude angle of aircraft is changed from small to big, more from large to small, repeats back and forth secondary; Measuring system is according to the data of each component output signal of collection strain balance of certain even continuous synchronization of acquisition rate and the data of attitude angle transducer output signal simultaneously;
(2) computing machine carries out the cross correlation function computational analysis to the data of each component output signal of strain balance and the data of attitude angle transducer output signal, obtains each component electric signal of strain balance of collection and the delay time difference between the attitude angle transducer electric signal;
(3) during wind tunnel test, acquisition system is according to the data of the acquisition rate acquisition test signal in step (1), then the delay time difference obtained according to step (2), the sequential of attitude angle transducer electric signal of take is standard time sequence, the data of each component electric signal of strain balance of recording are carried out to accurate synchronous the correction, finally obtain the test figure of Complete Synchronization.
2. a kind of method that realizes the test signals of wind tunnel precise synchronization according to claim 1, it is characterized in that, definite method of the attitude angle constant interval in described step (1) is, function rule according to each component of strain balance with the attitude angle conversion of aircraft, select the strain balance component to change the curve interval that approaches linear change with attitude angle.
3. a kind of method that realizes the test signals of wind tunnel precise synchronization according to claim 1, is characterized in that, the certain acquisition rate in described step (1) meets: the resolution of acquisition rate >=1/ time.
4. a kind of method that realizes the test signals of wind tunnel precise synchronization according to claim 1, is characterized in that, described step (2) specifically comprises the following steps:
(2.1) computing machine from synchronous acquisition to data isolate the time dependent curvilinear function of each component of balance and the time dependent curvilinear function of attitude angle;
(2.2) according to the cross correlation function formula
, calculate respectively the cross correlation function of the output signal function of the output signal function of each component of strain balance and attitude angle transducer; X in formula (t) is the output signal function of attitude angle transducer, and y (t) is respectively the output signal function of each component of strain balance, and t is the time, and T is the total duration of sampling;
(2.3) calculate cross correlation function R
xy(τ) value of the τ at place, top, this value is exactly the delay time difference between strain balance component electric signal and attitude angle transducer electric signal.
5. a kind of method that realizes the test signals of wind tunnel precise synchronization according to claim 1, it is characterized in that, further comprising the steps of: as the data of the data of each component output signal of strain balance of collecting and attitude angle transducer output signal to be carried out to nothing and postpone digital filtering and process, eliminate the noise that acquisition system is brought into.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210036066.7A CN102539107B (en) | 2012-02-17 | 2012-02-17 | Method for accurately synchronizing test signals of wind tunnel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210036066.7A CN102539107B (en) | 2012-02-17 | 2012-02-17 | Method for accurately synchronizing test signals of wind tunnel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102539107A CN102539107A (en) | 2012-07-04 |
| CN102539107B true CN102539107B (en) | 2014-01-01 |
Family
ID=46346552
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210036066.7A Expired - Fee Related CN102539107B (en) | 2012-02-17 | 2012-02-17 | Method for accurately synchronizing test signals of wind tunnel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102539107B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111879493A (en) * | 2020-07-15 | 2020-11-03 | 清华大学 | Flow field data measuring device, measuring method and measurement control system |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104111157B (en) * | 2014-07-14 | 2017-03-15 | 中国空气动力研究与发展中心高速空气动力研究所 | A kind of method for checking wind tunnel instrumentation initial reading |
| CN104932565B (en) * | 2015-06-04 | 2017-06-06 | 中国空气动力研究与发展中心高速空气动力研究所 | A kind of temporary stamp injector powered transonic wind tunnel flow field control structure of high accuracy |
| CN106706256B (en) * | 2017-02-14 | 2019-01-04 | 中国科学院力学研究所 | A kind of hypersonic aircraft component separation wind tunnel experiment synchronizing exploder |
| CN108332937B (en) * | 2018-02-08 | 2020-04-14 | 中国空气动力研究与发展中心高速空气动力研究所 | Wind tunnel continuous variable attack angle force measurement test data correction method |
| CN109000879B (en) * | 2018-06-27 | 2020-07-07 | 中国空气动力研究与发展中心高速空气动力研究所 | Wind tunnel balance temperature drift correction method |
| CN110132527B (en) * | 2019-06-24 | 2020-11-20 | 中国空气动力研究与发展中心高速空气动力研究所 | Balance signal-based model vibration monitoring method in wind tunnel test |
| CN111551342B (en) * | 2020-03-13 | 2021-10-01 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for realizing accurate synchronization of digital signals in wind tunnel test |
| CN112834161B (en) * | 2021-02-04 | 2024-02-23 | 中国空气动力研究与发展中心空天技术研究所 | Wind tunnel measurement data processing method based on feature extraction |
| CN114323540B (en) * | 2021-12-01 | 2023-05-23 | 中国空气动力研究与发展中心低速空气动力研究所 | Half-mould blowing high-lift wind tunnel test method and device for conveyor |
| CN114323542B (en) * | 2022-03-08 | 2022-05-13 | 中国空气动力研究与发展中心低速空气动力研究所 | Multi-signal acquisition synchronization method for wind tunnel dynamic test |
| CN114785445B (en) * | 2022-06-20 | 2022-09-09 | 中国空气动力研究与发展中心低速空气动力研究所 | Clock synchronization implementation method of wind tunnel pressure measurement system |
| CN114894423B (en) * | 2022-06-21 | 2023-03-03 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for measuring and analyzing acoustic modal propagation characteristics of compressible fluid of subsonic wind tunnel |
| CN115014696B (en) * | 2022-08-08 | 2022-10-25 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for synchronous acquisition and integrated processing of wind tunnel multi-signal source data |
| CN115508040B (en) * | 2022-11-17 | 2023-03-10 | 中国空气动力研究与发展中心高速空气动力研究所 | Synchronous parallel acquisition system for data of speed field and temperature field and application method |
| CN117272593B (en) * | 2023-08-24 | 2024-04-05 | 无锡北微传感科技有限公司 | Wind tunnel test data analysis processing method |
| CN117647374B (en) * | 2024-01-25 | 2024-04-16 | 中国空气动力研究与发展中心高速空气动力研究所 | Method for obtaining migration speed of high-speed jet shear layer based on dynamic pressure data |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1022778C (en) * | 1991-08-03 | 1993-11-17 | 北京光电技术研究所 | Direct real-time measuring method for angle of side slip of wind tunnel |
| JPH09257635A (en) * | 1996-03-21 | 1997-10-03 | Mitsubishi Heavy Ind Ltd | Apparatus for measuring load if moving body |
| CN1112579C (en) * | 1999-06-04 | 2003-06-25 | 合肥工业大学 | Real-time dynamic correcting system of multi-dimension force sensor |
| JP2003035628A (en) * | 2001-07-25 | 2003-02-07 | Mitsubishi Heavy Ind Ltd | Rotary apparatus and method for wind tunnel test |
| CN201689341U (en) * | 2010-03-30 | 2010-12-29 | 江苏技术师范学院 | Portable model attitude control device for low-speed wind tunnels |
| CN102012308B (en) * | 2010-05-19 | 2012-01-11 | 北京航空航天大学 | Method for jointly and synchronously measuring velocity/pressure during pitching/rolling movement of model |
-
2012
- 2012-02-17 CN CN201210036066.7A patent/CN102539107B/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111879493A (en) * | 2020-07-15 | 2020-11-03 | 清华大学 | Flow field data measuring device, measuring method and measurement control system |
| CN111879493B (en) * | 2020-07-15 | 2021-06-08 | 清华大学 | Flow field data measuring method and measurement control system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102539107A (en) | 2012-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102539107B (en) | Method for accurately synchronizing test signals of wind tunnel | |
| CN106989812A (en) | Large fan blade modal method of testing based on photogrammetric technology | |
| CN102654771B (en) | Automatic calibration method and system of analog channel | |
| CN107167559B (en) | A method of beam type bridge structure damage reason location is carried out using dual sensor | |
| CN105258829A (en) | Underground engineering model test internal space stress measuring device and method | |
| CN102043091A (en) | Digitized high-precision phase detector | |
| CN104534953A (en) | Method for measuring three-dimensional relative displacement through guyed displacement sensors | |
| CN105737793B (en) | Rolling angle measurement unit and measuring method | |
| CN103940577B (en) | A kind of appraisal procedure of wind tunnel test balance based on acceleration signal energy | |
| CN105423977A (en) | Hydraulic press slider detection device and detection method thereof | |
| CN106597003A (en) | Method for measuring ultrasonic bullet flight track via shock waves | |
| CN105510891A (en) | In-orbit modal identification method for synthetic aperture radar of satellite | |
| CN202720273U (en) | High-precision phase difference detection device | |
| CN103822768B (en) | A kind of ultra-low-frequency horizontal is to the static equalising means of shaking table guide rail irregularity | |
| CN109556505A (en) | The online Fast Calibration system and method for miniature oil film thickness based on capacitance principle | |
| CN102866031A (en) | Method for testing response relation of load position and bridge | |
| CN109297674A (en) | Pilot system is continuously measured based on pressure scanning valve model surface pressure | |
| CN103376128A (en) | Position sensor automatic checking device | |
| CN209399919U (en) | The online Fast Calibration system of miniature oil film thickness based on capacitance principle | |
| CN104635246A (en) | System and method for detecting dynamic range of satellite navigation signal | |
| CN101598540A (en) | 3-D positioning method and 3 D positioning system | |
| CN103940576B (en) | The appraisal procedure of a kind of wind1 tunnel trial balance based on acceleration signal approximate entropy | |
| CN203502039U (en) | Automatic rotating speed verifying device | |
| CN107600357B (en) | A kind of high-precision, which is faced upward, sweeps formula drauht detection system and its working method | |
| CN103179606A (en) | Dotting driving test method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140101 Termination date: 20170217 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |